On 17.03.25 11:07, Liu Ye wrote:
From: Liu Ye <liuye@xxxxxxxxxx>
The function kpageflags_read and kpagecgroup_read is quite similar
to kpagecount_read. Consider refactoring common code into a helper
function to reduce code duplication.
Signed-off-by: Liu Ye <liuye@xxxxxxxxxx>
---
V2 : Use an enumeration to indicate the operation to be performed
to avoid passing functions.
---
---
fs/proc/page.c | 166 +++++++++++++++++--------------------------------
1 file changed, 58 insertions(+), 108 deletions(-)
diff --git a/fs/proc/page.c b/fs/proc/page.c
index a55f5acefa97..66f454330a87 100644
--- a/fs/proc/page.c
+++ b/fs/proc/page.c
@@ -22,6 +22,14 @@
#define KPMMASK (KPMSIZE - 1)
#define KPMBITS (KPMSIZE * BITS_PER_BYTE)
+enum kpage_operation {
+ KPAGE_FLAGS,
+ KPAGE_COUNT,
+#ifdef CONFIG_MEMCG
+ KPAGE_CGROUP,
+#endif
+};
+
static inline unsigned long get_max_dump_pfn(void)
{
#ifdef CONFIG_SPARSEMEM
@@ -37,19 +45,17 @@ static inline unsigned long get_max_dump_pfn(void)
#endif
}
-/* /proc/kpagecount - an array exposing page mapcounts
- *
- * Each entry is a u64 representing the corresponding
- * physical page mapcount.
- */
-static ssize_t kpagecount_read(struct file *file, char __user *buf,
- size_t count, loff_t *ppos)
+static ssize_t kpage_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos,
+ enum kpage_operation op)
{
const unsigned long max_dump_pfn = get_max_dump_pfn();
u64 __user *out = (u64 __user *)buf;
+ struct page *ppage;
unsigned long src = *ppos;
unsigned long pfn;
ssize_t ret = 0;
+ u64 info;
pfn = src / KPMSIZE;
if (src & KPMMASK || count & KPMMASK)
@@ -59,19 +65,29 @@ static ssize_t kpagecount_read(struct file *file, char __user *buf,
count = min_t(unsigned long, count, (max_dump_pfn * KPMSIZE) - src);
while (count > 0) {
- struct page *page;
- u64 mapcount = 0;
-
- /*
- * TODO: ZONE_DEVICE support requires to identify
- * memmaps that were actually initialized.
- */
- page = pfn_to_online_page(pfn);
- if (page)
- mapcount = folio_precise_page_mapcount(page_folio(page),
- page);
-
- if (put_user(mapcount, out)) {
+ ppage = pfn_to_online_page(pfn);
+
+ if (ppage) {
+ switch (op) {
+ case KPAGE_FLAGS:
+ info = stable_page_flags(ppage);
+ break;
+ case KPAGE_COUNT:
+ info = folio_precise_page_mapcount(page_folio(ppage), ppage);
+ break;
+#ifdef CONFIG_MEMCG
+ case KPAGE_CGROUP:
+ info = page_cgroup_ino(ppage);
+ break;
+#endif
In general, LGTM.
I do wonder if we should just get rid of the two "#ifdef CONFIG_MEMCG" by adding
a stub for page_cgroup_ino().
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 57664e2a8fb7b..24248f4dcc971 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1788,6 +1788,11 @@ static inline void count_objcg_events(struct obj_cgroup *objcg,
{
}
+static inline ino_t page_cgroup_ino(struct page *page)
+{
+ return 0;
+}
+
#endif /* CONFIG_MEMCG */
#if defined(CONFIG_MEMCG) && defined(CONFIG_ZSWAP)
--
Cheers,
David / dhildenb
